Carriage positioning mechanism for grinding machines



July 11, 1933. V B; STOWELL 1,919,147

CARRIAGE POSITIONING MECHANISM FOR GRINDING MACHINES Filed Nov. 17, 1930,3 Sheets-Sheet 1 INVENTOR.

BYRON F S7'0WELL J7 BY W A TTORN E YS.

July 11, 1933. s. F. STOWELL CARRIAGE POSITIONING MECHANISM FOR GRINDINGMACHINES 1950 3 Sheets-Sheet 2 Filed Nov. 17,

1N VEN TOR. Brm FSMWELL ATTORNEY July 11, 1933. 5' STOWELL 1,918,147

CARRIAGE POSITIONING MECHANISM FOR GRINDING MACHINES Filed Nov 17, 19305 Sheets-Sheet 5 44 23 1 z; 70 7/ a; 23 67 M 37 .5 //,Z //l g 1 2r ///I/Ag i@i J 5 0 O i 5 $1 x I I i I m I IN VEN TOR.

A TTORNEYS.

Patented July 11, 1933 lrrren s'rar rarest r'r ca .w LL, or BI-.Ni "NEcciirranv,

caianraen Posmroni'i em ss; assienoa T van n'omvmn xmssacnosnrrs, Aoonrona'rron OF 7G HESEAISIISIKE GRINDER MACHINES Application. filedNovember 1?, 1930. Serial No. 496,178.

a .rhinr-s of this type it is necessary to pro ide an accuratemechanicalfeed in a direction at right angles to the axis of the grindmg wheel sothat the wheel may be fed gr. d y and progressively against he work as gproceeds. ,l hen it desired to remove the t: from the worln two motions1 righ angles to each other are necessary. these is a rapid motion inthe same fixer-lion as the slow feed but generally separate fromthistced in order to provide quick- The second is. at right angles toother words parallel to the axis of the grinding wheel. The lattermotion serves to withdraw the grinding wheel axially out of the ballbearing ring which is being mind and can only be made after the firstmotion is completed so that the grinding wheel will clear the annularground recess in the bearing race.

placed in position for the start of a grinding operation.

One object of the invention is to provide a single com rol by which thetwo rough positioning motions oil. the tool head may be accomplished. Afurther object is to provide in :hanisni which will automatically resetthe accurate cross feed whenever the grinding tool is witlnjlrawn fromits operative position. A further obj octis to provide mechanismgoverned by this same control by which the machine will be automaticallystopped by the operation of shifting the tool out of grinding position.A further object is to provide an interlocking control between thevarious motions so that the machine cannot be operated in a manner tocause injury to the work. Other and further objects will An inversesequence of motions will occur when the wheel 1S bein D freely mountedupon appear from the following description and claims. Y

The invention will now be described 1n connection with the accompanyingdrawings,

in which:

Fig. 1 1s a top plan view of the tool head end of a grinding machineembodying my invention Fig. 2 is a side elevation thereof;

1 i g. 3 is a partial top plan on an enlarged scale showing the partsin, a different position oi operation;

Fig. 4 is a similar View showing a still d i .lierent positi on ofoperation Fig. 5 is a section on line 5-5 of Fig. l;

F lg. (S a partial bottom plan View taken on line 66 of Fig. 2; i

Fig. '2' is a section on line 77 of Fig. 4;

Fig. 8 is a partialrear elevation of the machine; and i i Fig. 9 adetail on line 99 or Fig.7.

The machine is mounted upon a frame 10 waich. at its tool head endcarries. ways 11 (Fig. 7). Slnling in these waysis a slide 12 whichconstitutes the means for moving the tool head in a direction parallelto the axis ol the rinding wheel An accurate limiting position of thisslide is determined by means of a bracket 13 ig. 2) overhanging theframe and carrying stop screw 14, sothat when the slide is moved thedesired amount the screw will abut the frame and stop any furthermovement.

Y Mounted in the top of the slide 12 is a sleeve 15 (Fig. 7) having avertical bore in which rotates a shaft 16. The lower end of this shaftcarries a gear 17 meshing with a rack 18 fixed to the frame. By rotatingthe shaft 16 it is thus possible to move the slide 12 along its wayswith a comparatively rapid motion. In order to rotate the shaft, anarm19 is splitas at 20 6) and is drawn together around the shaft by meansof a bolt 21. The arm 19 is not directly moved by the operator, but isactuated by connections to be described by a second arm 22 (Fig. 7)shaft 16. The arm 22 has a cam 23 secured to it by a bolt 24: andserving a purpose to be describedlater. Bearing upon the top of the camis a cap screw threaded into the shaft and thus serving to maintain boththe arm and the cam in position upon the shaft, while permitting theirfree rotation in unison. Upon the lower side of the arm 22 is a bracket26 (Figs. 3 and 6) to which is pivoted at 27 a latch 28. This latch isnormally drawn by a spring 29 into the position shown in Figs. 3 and 6where its end bears against a beveled portion of the lower arm 19. Aslong as the latch remains in this position, movement of the arm 22 fromthe position of Fig. 1 to that of Fig. 3 will cause the arm 19 to movewith it and through the rack and pinion described will causereciprocation of the slide 12 in the ways 11.

hen the slide 12 has reached the position of Fig. 3, its stop screw 14is abutted against the frame, preventing any further movement in thatdirection. This of course stops the movement of the arm 19 and also ofthe arm 22 which is at this moment connected to the first arm by thelatch 28. In order to continue the motion of the upper arm and pro- 1duce the further positioning movements of the machine which will bedescribed later, it is necessary to disengage the latch 28 from thelower arm. For this purpose the latch is provided at its lower side witha boss 31 connected by a link 32 (Figs. 5 and 6) with j a boss or yoke33 fixed to the lower side of a shaft 34 freely rotatable in the arm 22.At its outer end this shaft has a handle 35 (Fig. 3) secured to it by akey 36 and screw 37. If the handle is turned so that its top moves tothe left (as viewed in Fig. 3), the latch 28 will be swung and its endmoved beyond the end of the lower arm 19. Motion of the upper arm canthen be continued as indicated in Fig.4.

In order to hold the lowerarm 19 in position after it has beendisengaged by the upper arm, a latch 38 (Fig. 3) having a hooked portion39 adapted to engage a latch plate 40 is provided. The latch plate isadjustably mounted by a bolt 41 in an arcuate T-slot 42 formed in aflange 43 of the sleeve 15. The tail 44 of this latch engages a stop 45carried by the bracket 26. The latch is pivoted at 46 (Fig. 6) to thelower arm and is urged into latching position by a spring 47. The latchplate 40 is so adjusted in its slot that the latch will just engage itas stop 14 strikes the frame. Having once been set, it may thereafter beleft in its adjusted position until the setting of the stop 14 ischanged.

Before considering the remaining functions of the control arms, it isnecessary to describe the cross slide mechanism which carries the toolhead. Upon the top of the slide 12 are formed ways 50 (Figs. 2 and 8)upon which reci'procates an intermediate slide 51. A'nut 52 secured tothis slide has threaded into it a screw threaded shaft 53 which is heldagainst axial movement in the slide 12 and which bears a ratchet wheel54. vThis ratchet wheel may be rotated automatically in the usual way tocause a slow and accurate cross feed movement of the slide 51. Upon thetop of the slide 51 are formed ways 55 in which run a top slide 56. Thetop slide itself is preferably provided with ways 57 in which a separatemotor slide, not shown, is mounted. The tool spindle 59 carrying thegrinding wheel 60 is supported in this slide 56.

To the rear end of the intermediate slide 51 is secured a plate 61 (Fig.3) upon which the nut 52 may conveniently be mounted. The plate 61 alsocarries a stop screw 62 positioned to lie in the path of the top slide56 and limit its outward movement. The plate also is apertured to permitthe passage of a stud 63 secured to the top slide and bearing stop nuts64 serving to limit travel of the top slide in the opposite direction.

A stud 65 is secured to the top slide and has a fixed collar 66 and amovable collar 67 pressed toward it by a spring 68 compressed betweenthe movable collar 67 and a fixed collar 69. The end of an arm 7 Opivoted at 71 upon a bracket 72 extending from the slide 12 is aperturedto receive the stud 65 and is positioned between the collars 66 and 67.The arm is formed as a bell crank and its other end is provided with aflat surface 7 3 against which the cam 23 is adapted to bear. As the campresses the adjacent end of the bell crank to the left as viewed in Fig.3, the other arm of the bell crank will exert a pull on. the slide 56and will cause it to be drawn outwardly toward the stop 62. The cam isprovided with an arc shaft slot 74 through which passes the bolt 24previously mentioned, thus permitting the cam to be adjusted in anydesired angular position. In order to keep the surface 73 pressed towardthe cam, a spring 76 is provided, compressed between a fixed collar 77and a movable collar 78 on a rod 79 secured to the intermediate slide51.

Mechanism isalso provided for resetting the slow cross feed given by theshaft 53 when the slides are moved to their inactive position. For thispurpose a gear 80 (Fig. 2) is secured to the shaft 53 and has meshingwith it a train of gears 81, 82 and 83. Adapted to mesh with the last ofthese gears is a rack 84 pivoted at 85 to the frame so that it mayoscillate between a position meshing with the gear 83 and a positionjust below it. A lifter 86 is pivoted to the frame at 87 below the rackand has a rod 88 connected to it which passes through a bracket 89projecting downwardly from the slide 12. Vithin a recess in the bracketare fiber blocks 90 and 91 (Fig. 7) encircling the rod 88 and pressedtogether by a spring 92 held in place by a cap 93. The blocks bearagainst the rod with just sulficient force to exert a frictional dragupon it.

active position, the lifter will be rotated in the opposite way and willraise the rack so that it will mesh with the gear 83. Since this gearmoves with the slide 12 and the rack is stationary, a rotation will beimparted to 1 the shaft 53 on a rearward motion of the slide. This issufficient to cause the amount of forward rotation given to the shaft 53dur-v ing the feeding movement to be compensated for.

It will be noted from the description above that a single motion of thehandle from the position of Fig. 4 to that of Fig. 1 will first move thegrinding wheel in a direction at right angles to its axis to disengageit from the work piece which has just been ground, and then will movethe wheel in the direction of its axis to withdraw it from the localityof the work piece and permit the latter to be removed without hindrance.To remove the work piece, however, it is necessary to stop its rotationand also the oscillation of the head which carries it. This rotation andoscillation may be imparted to the work head by any suitable mechanismoperated from a main shaft 190 9). A suitable mechanism is shown in thepatent to Van Norman, No. 1,722,691, July 30, 1929, the shaft 190 in thepresent case corresponding to the shaft S of the patent. Mounted uponthe shaft 190 a tight pulley 191, a loose pulley 192, and a brake disk 7193. A belt from any suitable power source passes over the pulleys,being maintained under the control of a belt shifter 94 carried by asliding rod 95. A brake 96 is also carried by the rod so that when thebelt is shifted to the loose pulley not only will the driving force becut off from the shaft but a braking force will be applied to bring itto rest quickly.

The rod 95 is constantly urged towards the left in Fig. 9 by a spring97. An arm 98 is secured to a short pivot shaft 99 and has a pin andslot connection 100 with the rod. Also secured to the shaft 99 is an arm101 joined by a link 102 (Fig. 7) with a treadle 103. By depressing thetreadle, the rod 95 is shifted in a direction to cause the belt to bemoved onto the tight pulley. \Vhen once depressed it is neld in thatposition by a rod 104 sliding in the frame and urged to the left in Fig.7 by a spring 105 compressed between the frame and a collar 106 on therod. In its left hand position the end of the rod projects beyond theside of the arm 101, the motion of the rod being limited by contact ofthe collar with the face of the arm (Fig.

The end of the rod 10% remote from the collar carries a. rounded disk107 (Fig. 7) which lies adjacent the lower end of an arm arm 101.

from the first slide moving mechanism, and

108 secured to a "shaft 109 ourn-al'ed in a bracket 110 securedto theslide 51. Asecond arm 111 secured to the shaft is fastened at its upperend to'a rod 112 projecting from the slide 56. 'Asthe latter slide ismoved to free the grinding wheel from its work, the disk 107 is struckby the arm 108 and pushed far enough to the right in Fig. 7 to withdrawthe end of rod 104 from its position beside the The rod 95 is thus freedfor motion under the influence of the spring 97 in a direction to shiftthe belt to the loose pulley 92. By this mechanism the power to themachine is placed under the control of the operating handle A singleswing of this handle moves the grinding wheel transversely to free itfrom the work, shuts 05 the power, moves the grinding wheellongitudinally, and resets the slow feeding mechanism.

hat I claim is:

1. A grinding machine having a pair of slides at an angle to each other,a single handle movable through an arc, mechanism operal le by thehandle while moving through one portion of said arc for moving oneslide, and mechanism operable by the handle while moving through anotherportion of said are for moving the other slide. I

2. A grinding machine having a work head, a first slide movable towardand away from the work head, a second slidemovable upon the first at anangle thereto, a tool head carried by thesecond slide, a handle pivotedfor rotation upon the first slide, mechanism operable by the handleduring one portion of its rotation for moving the first slide, andmechanism operable by the handle during another part of its rotation formoving the second slide.

3. A grinding machine having a work head, a first slide movable towardand "away from the work head, asecond slide movable upon the first at anangle thereto, a tool head ca-rriedloy the second slide, a. handlepivoted for rotation upon the first slide, a stop limiting the motion ofthe first slide, mechanism operable by the handle during the first partof its rotation for moving the first slide, a device carried by thehandle for releasing it mechanism operable by the continued rotation ofthe handle for movingthe second slide.

4. A grinding machine as claimed in claim 3 in which the releasingdevice carried by the handle comprises a manipulable element rotatableto cause release. I

5. A grinding machine comprising a frame, a slide mounted 011 the frame,a second slide mounted on the first at an angle to it, a shaft journaled in the first slide, a rack and pinion connection between theshaft and the frame, a handle rotatable on the shaft, pawl mech anismreleasably connecting the handle to the shaft, a bell crank pivoted onsaid slide, a

cam carried by the handle acting on the bell crank to rock it upon itspivot, and connections betweenthe bell crank and the second slide.

(3. A grinding machine comprising a work head, a first slide, means formoving the first slide towards and away from the work head, a secondslide movable u )011 the first slide at an angle thereto, a thirdslidemovable upon the second slide, a tool head carried by the third slide,mechanism for moving the third slide upon the second slide to place thetool head in or out of operative relation with the work head, means formoving the second slide upon the first slide with a slow tool-feedingmovement, and mechanism automatically operable upon the movement of thefirst slide away from active position to reverse the slow tool-feedingmovement of the second slide and return it substantially to its originalposition. 7. A grinding machine having rotary work holding and wheelcarrying heads, means for moving one head relatively to the other indirections substantially parallel with and right angularly to the axisof its rotation, slow feeding meclninisni for moving said head in onedirection and. a single lever controlling, through progressive movementsthereof, mechanisms operable to effect a rapid withdrawal of said, headin each of its directions of movement and to impart an ac celeratedreverse movement to said feeding mechanism.

8. A grinding machine having rotary work means for supporting one ofsaid heads for movement relative tothe other in two directions, onesubstantially parallel to and the other substantially at right angles tothe axis of rotation of the head, mechanism {or moving said head at aslow rate of feed in one of said directions, a progressively movablemember, and mechanisnr actuable by progressive movementoii said'memherfor moving said head-in a sequence of quick acting movements in both ofsaid two direct-ions.

10. A grinding machine or the like having rotary work holding and toolcarrying heads.-

means for supporting one of said headsfor movement relative to the otherin two directions, one :nibstantially parallel to and the othersubstantially at right angles to the axis of rotation of the head,mechanism for moving said head at a slow rate of feed in one of saiddirections, a progressively movable member. mechanism actuable byprogressive movement ot-said member for moving said head in a sequenceof quick acting movements in both of said two directions, and separatcmechanism operable through movement of said head in one of saiddirections of travel. to effect a reversed and accelerated movement tosaid slowfeeding mechanism.

In testimony whereof I have aflixed my signature.

BYRON r. sToWnLL.

